Quicken 2017 Deluxe should be able to convert any Quicken 2015 data
file into Quicken 2017 data file format. Obviously, you will not be
able to access the Home and Business specific functionality but the
data will be preserved and available should you subsequently upgrade
Extending Sherlock's reply, with which I concur, your H&B specific accounts will become just regular accounts in Deluxe ... but the data will still be there.
SHOULD at some point, you want to return to H&B, you can "unlock" the H&B functions (for a fee) from within Q.